Field of the Invention
The present invention relates to electromagnetic relays and, more specifically, to electromagnetic relays suitable for high temperature use.
A relay with a coil body serving as basic body, a U-shaped core yoke, and a plate-formed armature is known, for example, from the document WO 90/09028. The switching spring there is immediately connected to the armature, and, in addition, welded at the yoke via an angled off section. It serves as armature bearing spring as well as electric connection for the movable contacts.
In using such known relays at high heat load, namely at high surrounding temperature and/or with high self-heating due to the coil current and/or a high load current, the cross sections for the load circuit are necessarily overdimensioned in order to keep the dissipated power small. In addition, the coil has to be designed to reduce the dissipation of power and to provide a high winding wire volume. The contact and armature reset spring that is necessary in the standard construction has to be created from a material with slight relaxation behavior at high temperatures, i.e., for example from an expensive beryllium-alloyed copper spring material. These parameters physically limit the miniaturizing of the electromechanical relays for large loads at high ambient temperature.